Long-term outcomes of combination therapy with stereotactic body radiation therapy plus cryoablation using liquid nitrogen for stage I non-small cell lung cancer with tumors ≥2 cm.

Abstract

Radiation and ablation therapy are used to treat stage I non-small cell lung cancer. However, the local control and survival rates remain unsatisfactory for tumors ≥2 cm. Therefore, this study explored the effectiveness of combination therapy of stereotactic body radiation plus cryoablation in this patient population. This retrospective observational study included patients with stage I non-small cell lung cancer ≥2 cm who underwent stereotactic body radiation therapy followed by cryoablation between 2015 and 2023. All tumors were pathologically diagnosed before treatment. Patients received stereotactic body radiation therapy (40-60 Gy/4-10 fractions, median biological effective dose: 100 Gy), followed by cryoablation using liquid nitrogen within 3 weeks of radiation therapy. Study outcomes included local control and survival rates, as well as adverse events. Sixty-four patients were included in the study. The mean tumor diameter was 2.7 ± 0.5 (range, 2.0-4.0) cm. The median follow-up duration was 74 (range, 3-111) months. Five patients (8%) experienced local recurrence after treatment (range: 8-61 months). The 5-year local control and overall survival rates were 93% and 74%, respectively. No patient experienced treatment-related mortality. The most frequent complication was post-cryoablation pneumothorax (40%), with a median drainage period of 2 days. Five patients (8%) experienced radiation pneumonitis; four patients had grade 2 severity and one had grade 3 severity, but all these patients recovered without sequelae. Combination therapy with stereotactic body radiation therapy followed by cryoablation is a feasible and favorable treatment for stage I non-small cell lung cancer with tumors ≥2 cm.